Although a round mirror might be a great artist/attractive choice looking at lighting in your bathroom mirror with lighting would be a better choice if you search Houzz for bathroom mirror with light their were some great designs Pendant would not help when do makeup or beauty routine You wouldn’t need those other accessories to make it fit in - more money for something elde

two more ideas for your family bathroom keeping the door the same. 1. has room for a 600 towel and bathroom items cupboard. 2. could have a nib wall across the room behind the bath across to the shower / toilet wall with a sliding door to separate the toilet and still allow the vanity and shower to be used. Or the nib wall between the bath and vanity could be flush with the vanity or just no nib wall between the vanity and the bath, so many choices

unable to read all the dimensions my suggestions have simplified the shape of the building and based on estimated room sizes are aimed at improving comfort by separating some areas (eg study and lounge) for quiet activities and if you added furniture to suit your lifestyle and activities (eg not sure how you would want to furnish the cinema and bar) would help you to ensure rooms are the best size and shape (eg downstairs bedroom could be used for a guest room so i've included private access to the bathroom)..the zen room could be included with the master suite by moving the doors across the upstairs hallway...the rearranged cloak room to better suit the likely easy walking path from car inside with groceries and the powder room more likely used from the study and lounge when there's an extra bathroom at the back of the house.....luckily you have ideal north facing main rooms but, unless there are great views i would be cautious about balconies and wide expanses of glass to the east or west (or consider external sun screens) and depending on budget there would be lots of option to reduce the overall size without changing the basic floorplan

I’d start by position couch with its back to hallway and solid wall. Then see how the floor space works for you. Long lounge rooms are hard. But this should give more flexibility for a larger crowd using some flexible furniture. Maybe piano and bar/buffet along the new side wall with just a highline window